Combination of CFD and DOE to analyze and improve the mass flow rate in urinary catheters

The urinary catheter is a thin plastic tube that has been designed to empty the bladder artificially, effortlessly, and with minimum discomfort. The current CH14 male catheter design was examined with a view to optimizing the mass flow rate. The literature imposed constraints to the analysis of the urinary catheter to ensure that a compromise between optimal flow, patient comfort, and everyday practicality from manufacture to use was achieved in the new design. As a result a total of six design characteristics were examined. The input variables in question were the length and width of eyelets 1 and 2 (four variables), the distance between the eyelets, and the angle of rotation between the eyelets. Due to the high number of possible input combinations a structured approach to the analysis of data was necessary. A combination of computational fluid dynamics (CFD) and design of experiments (DOE) has been used to evaluate the "optimal configuration." The use of CFD couple with DOE is a novel concept, which harnesses the computational power of CFD in the most efficient manner for prediction of the mass flow rate in the catheter. Copyright © 2009 by ASME.

Caractérisation des matériaux latéritiques pour une meilleure utilisation en Afrique

In spite of the fact that the laterite masonry was often used for building, during the colonial period, the laterite rock is rarely studied. To resolve the economic and environmental problems, concerning the concrete or cinder block construction in Africa, this material can be again a local resource. The objective is to determine the hydro-thermo-mechanical properties of laterite rocks linking with the local geological conditions, to investigate the possibilities to be used in construction housing, sufficiently able to resist to limited loads and to give thermal comfort inside. Some preliminary results are presented here.

Solvent induced phase inversion-based in situ forming controlled release drug delivery implants

In situ forming (ISF) drug delivery implants have gained tremendous levels of interest over the last few decades. This is due to their wide range of biomedical applications such as in tissue engineering, cell encapsulation, microfluidics, bioengineering and drug delivery. Drug delivery implants forming upon injection has shown a range of advantages which include localized drug delivery, easy and less invasive application, sustained drug action, ability to tailor drug delivery, reduction in side effects associated with systemic delivery and also improved patient compliance and comfort. Different factors such as temperature, pH, ions, and exchange of solvents are involved in in situ implant formation. This review especially focuses on ISF implants that are formed through solvent induced phase inversion (SPI) technique. The article critically reviews and compares a wide range of polymers, solvents, and co-solvents that have been used in SPI implant preparation for control release of a range of drug molecules. Major drawback of SPI systems has been their high burst release. In this regard, the article exhaustively discusses factors that affect the burst release and different modification strategies that has been utilised to reduce the burst effect from these implants. Performance and controversial issues associated with the use of different biocompatible solvents in SPI systems is also discussed. Biodegradation, formulation stability, methods of characterisation and sterilisation techniques of SPI systems is comprehensively reviewed. Furthermore, the review also examines current SPI-based marketed products, their therapeutic application and associated clinical data. It also exemplifies the interest of multi-billion dollar pharma companies worldwide for further developments of SPI systems to a range of therapeutic applications. The authors believe that this will be the first review article that extensively investigate and discusses studies done to date on SPI systems. In so doing, this article will undoubtedly serve as an enlightening tool for the scientists working in the concerned area.

IDEAhaus: A Comfortable Home for the UK’s Future Climate

IDEAhaus:
A Comfortable Home for the UK’s Future Climate

This paper describes the result of a project to develop climate adaptation design strategies funded by the UK’s Technology Strategy Board. The aim of the project was to look at the threats and opportunities presented by industrialised and lightweight housebuilding techniques in the light of predicted increases in flooding and overheating. This case study presents detailed concept designs for a future systemised housing product which can be Industrialised, Delightful, Efficient and Adaptable; an IDEAhaus.
Keywords: climate change adaptation, thermal comfort, passive cooling, flood residence, industrialised housing, mass customisation

Developing mathematics support for first-year engineering students with non-traditional mathematics backgrounds

A maths support system for first-year engineering students with non-traditional entry qualifications has involved students working through practice questions structured to correspond with the maths module which runs in parallel. The setting was informal and there was significant one-to-one assistance. The non-traditional students (who are known to be less well prepared mathematically) were explicitly contacted in the first week of their university studies regarding the maths support and they generally seemed keen to participate. However, attendance at support classes was relatively low, on average, but varied greatly between students. Students appreciated the personal help and having time to ask questions. It seemed that having a small group of friends within the class promoted attendance – perhaps the mutual support or comfort that they all had similar mathematical difficulties was a factor. The classes helped develop confidence. Attendance was hindered by the class being timetabled too soon after the relevant lecture and students were reluctant to come with no work done beforehand. Although students at risk due to their mathematical unpreparedness can easily be identified at an early stage of their university career, encouraging them to partake of the maths support is an ongoing, major problem.

A static test method to assess swivel seat strength in frontal impact

Mechanical swivel seat adaptations are a key aftermarket disability modification to any small-to medium-sized passenger vehicle. However, the crashworthiness of these devices is currently unregulated and the existing 20g dynamic sled testing approach is prohibitively expensive for prototype assessment purposes. In this paper, an alternative quasi-static test method for swivel seat assessment is presented, and two different approaches (free-body diagram and multibody modelling) validated through published experimental data are developed to determine the appropriate loading conditions to apply in the quasi-static testing.Results show the two theoretical approaches can give similar results for estimating the quasi-static loading conditions, and this depends on the seatbelt configuration. Application of the approach to quasi-static testing of both conventional seats and those with integrated seat belts showed the approach to be successful and easy to apply. It is proposed that this method be used by swivel seat designers to assess new prototypes prior to final validation via the traditional 20g sled test.

Automatic extraction of Reduced order models from CFD simulations for building energy modeling

Thermal comfort is defined as “that condition of mind which expresses satisfaction with the thermal environment’ [1] [2]. Field studies have been completed in order to establish the governing conditions for thermal comfort [3]. These studies showed that the internal climate of a room was the strongest factor in establishing thermal comfort. Direct manipulation of the internal climate is necessary to retain an acceptable level of thermal comfort. In order for Building Energy Management Systems (BEMS) strategies to be efficiently utilised it is necessary to have the ability to predict the effect that activating a heating/cooling source (radiators, windows and doors) will have on the room. The numerical modelling of the domain can be challenging due to necessity to capture temperature stratification and/or different heat sources (radiators, computers and human beings). Computational Fluid Dynamic (CFD) models are usually utilised for this function because they provide the level of details required. Although they provide the necessary level of accuracy these models tend to be highly computationally expensive especially when transient behaviour needs to be analysed. Consequently they cannot be integrated in BEMS. This paper presents and describes validation of a CFD-ROM method for real-time simulations of building thermal performance. The CFD-ROM method involves the automatic extraction and solution of reduced order models (ROMs) from validated CFD simulations. The test case used in this work is a room of the Environmental Research Institute (ERI) Building at the University College Cork (UCC). ROMs have shown that they are sufficiently accurate with a total error of less than 1% and successfully retain a satisfactory representation of the phenomena modelled. The number of zones in a ROM defines the size and complexity of that ROM. It has been observed that ROMs with a higher number of zones produce more accurate results. As each ROM has a time to solution of less than 20 seconds they can be integrated into the BEMS of a building which opens the potential to real time physics based building energy modelling.

Evidence reasoning for event inference in smart transport video surveillance

In this paper we present a new event recognition framework, based on the Dempster-Shafer theory of evidence, which combines the evidence from multiple atomic events detected by low-level computer vision analytics. The proposed framework employs evidential network modelling of composite events. This approach can effectively handle the uncertainty of the detected events, whilst inferring high-level events that have semantic meaning with high degrees of belief. Our scheme has been comprehensively evaluated against various scenarios that simulate passenger behaviour on public transport platforms such as buses and trains. The average accuracy rate of our method is 81% in comparison to 76% by a standard rule-based method.

Technological Learning in Developing Countries

Technological learning refers to the learning processes involved in improving the productive capabilities of an enterprise, sector or economy to enable it to produce higher quality goods or services with increasing levels of efficiency. Approaches to the study of technological learning include case studies of particular countries, sectors and firms; measures of export sophistication; and composite indicators of innovation and competitiveness. The present review draws on these approaches to provide an overview of the policies and practices that have been successful in different regions (East-Asia and Latin America) ; contexts (import substitution and liberalization) ; sectors (pulp and paper, IT services, electronics and passenger cars); and firms (Embrear and Lenovo). While it is clear that there is strong complementarity between domestic technological capability and the ability to absorb foreign technology, there is no simple policy recipe which is appropriate for all times, industries or places. Technological learning builds on and is shaped by what is already known. It requires time, space and resources all of which are influenced by the wider domestic and international context. The current international context is challenging but countries and firms have to find ways of moving forward despite the limited strategy space.

Automatic extraction of reduced-order models from CFD simulations for building energy modelling

Accurate modelling of the internal climate of buildings is essential if Building Energy Management Systems (BEMS) are to efficiently maintain adequate thermal comfort. Computational fluid dynamics (CFD) models are usually utilised to predict internal climate. Nevertheless CFD models, although providing the necessary level of accuracy, are highly computationally expensive, and cannot practically be integrated in BEMS. This paper presents and describes validation of a CFD-ROM method for real-time simulations of building thermal performance. The CFD-ROM method involves the automatic extraction and solution of reduced order models (ROMs) from validated CFD simulations. ROMs are shown to be adequately accurate with a total error below 5% and to retain satisfactory representation of the phenomena modelled. Each ROM has a time to solution under 20seconds, which opens the potential of their integration with BEMS, giving real-time physics-based building energy modelling. A parameter study was conducted to investigate the applicability of the extracted ROM to initial boundary conditions different from those from which it was extracted. The results show that the ROMs retained satisfactory total errors when the initial conditions in the room were varied by ±5°C. This allows the production of a finite number of ROMs with the ability to rapidly model many possible scenarios.

Tanker Mission Implication on a Civil Aerial Refuelling Transport System’s Benefit Evaluation

As the emphasis on initiatives that can improve environmental efficiency while simultaneously maintaining economic viability has escalated in recent years, attention has turned to more radical concepts of operation. In particular, the cruiser–feeder concept has shown potential for a new generation, environmentally friendly, air-transport system to alleviate the growing pressure on the passenger air-transportation network. However, a full evaluation of realizable benefits is needed to determine how the design and operation of potential feeder-aircraft configurations impact on the feasibility of the overall concept. This paper presents an analysis of a cruiser–feeder concept, in which fuel is transferred between the feeder and the cruiser in an aerial-refueling configuration to extend range while reducing cruiser weight, compared against the effects of escalating existing technology levels while retaining the existing passenger levels. Up to 14% fuel-burn and 12% operating-cost savings can be achieved when compared to a similar technology-level aircraft concept without aerial refueling, representing up to 26% in fuel burn and 25% in total operating cost over the existing operational model at today’s standard fleet technology and performance. However, these potential savings are not uniformly distributed across the network, and the system is highly sensitive to the routes serviced, with reductions in revenue-generation potential observed across the network for aerial-refueling operations due to reductions in passenger revenue.

Investigation into the potential of using micro gas turbines in plug-in hybrid electric vehicles

The transport sector is considered to be one of the most dependent sectors on fossil fuels. Meeting ecological, social and economic demands throughout the sector has got increasingly important in recent times. A passenger vehicle with a more environmentally friendly propulsion system is the hybrid electric vehicle. Combining an internal combustion engine and an electric motor offers the potential to reduce carbon dioxide emissions. The overall objective of this research is to provide an appraisal of the use of a micro gas turbine as the range extender in a plug-in hybrid electric vehicle. In this application, the gas turbine can always operate at its most efficient operating point as its only requirement is to recharge the battery. For this reason, it is highly suitable for this purpose. Gas turbines offer many benefits over traditional internal combustion engines which are traditionally used in this application. They offer a high power-to-weight ratio, multi-fuel capability and relatively low emission levels due to continuous combustion.

Development and Application of Medication Appropriateness Indicators for Persons with Advanced Dementia: A Feasibility Study

Background: No studies have been conducted in the UK context to date that categorise medications in terms of appropriateness for patients with advanced dementia, or that examine medication use in these vulnerable patients.

Objectives: The objectives of this study were to categorise the appropriateness of a comprehensive list of medications and medication classes for use in patients with advanced dementia; examine the feasibility of conducting a longitudinal prospective cohort study to collect clinical and medication use data; and determine the appropriateness of prescribing for nursing home residents with advanced dementia in Northern Ireland (NI), using the categories developed.

Methods: A three-round Delphi consensus panel survey of expert clinicians was used to categorise the appropriateness of medications for patients with advanced dementia [defined as having Functional Assessment Staging (FAST) scores ranging from 6E to 7F]. This was followed by a longitudinal prospective cohort feasibility study that was conducted in three nursing homes in NI. Clinical and medication use for participating residents with advanced dementia (FAST scores ranging from 6E to 7F) were collected and a short test of dementia severity administered. These data were collected at baseline and every 3 months for up to 9 months or until death. For those residents who died during the study period, data were also collected within 14 days of death. The appropriateness ratings from the consensus panel survey were retrospectively applied to residents’ medication data at each data collection timepoint to determine the appropriateness of medications prescribed for these residents.

Results: Consensus was achieved for 87 (90 %) of the 97 medications and medication classes included in the survey. Fifteen residents were recruited to participate in the longitudinal prospective cohort feasibility study, four of whom died during the data collection period. Mean numbers of medications prescribed per resident were 16.2 at baseline, 19.6 at 3 months, 17.4 at 6 months and 16.1 at 9 months. Fourteen residents at baseline were taking at least one medication considered by the consensus panel to be never appropriate, and approximately 25 % of medications prescribed were considered to be never appropriate. Post-death data collection indicated a decrease in the proportion of never appropriate medications and an increase in the proportion of always appropriate medications for those residents who died.

Conclusions: This study is the first to develop and apply medication appropriateness indicators for patients with advanced dementia in the UK setting. The Delphi consensus panel survey of expert clinicians was a suitable method of developing such indicators. It is feasible to collect information on quality of life, functional performance, physical comfort, neuropsychiatric symptoms and cognitive function for this subpopulation of nursing home residents with advanced dementia.

Energy and environmental forensic analysis for public buildings.

This paper outlines a forensic method for analysing the energy, environmental and comfort performance of a building. The method has been applied to a recently developed event space in an Irish public building, which was evaluated using on-site field studies, data analysis, building simulation and occupant surveying. The method allows for consideration of both the technological and anthropological aspects of the building in use and for the identification of unsustainable operational practice and emerging problems. The forensic analysis identified energy savings of up to 50%, enabling a more sustainable, lower-energy operational future for the building. The building forensic analysis method presented in this paper is now planned for use in other public and commercial buildings.

Evidential event inference in transport video surveillance

This paper presents a new framework for multi-subject event inference in surveillance video, where measurements produced by low-level vision analytics usually are noisy, incomplete or incorrect. Our goal is to infer the composite events undertaken by each subject from noise observations. To achieve this, we consider the temporal characteristics of event relations and propose a method to correctly associate the detected events with individual subjects. The Dempster–Shafer (DS) theory of belief functions is used to infer events of interest from the results of our vision analytics and to measure conflicts occurring during the event association. Our system is evaluated against a number of videos that present passenger behaviours on a public transport platform namely buses at different levels of complexity. The experimental results demonstrate that by reasoning with spatio-temporal correlations, the proposed method achieves a satisfying performance when associating atomic events and recognising composite events involving multiple subjects in dynamic environments.